<!DOCTYPE html>
<html>
<head>
	<title></title>
</head>
<body>

<script type="text/javascript">
//头条考题
var o = {
	a:10,
	b:{
		a:2,
		fn:function(){
			console.log( this.a ); // 2
			console.log( this );   //代表b对象
		}
	}
}
o.b.fn();
</script>
</body>
</html>